A display device such as a liquid crystal display device, which includes a display element with a memory function such as a self-luminous element or an electrophoretic element, and the like attract attention as a flat panel display device, and gradually began to appear in the market as practical devices. Examples of the self-luminous element include an organic light-emitting diode (OLED; also referred to as organic EL element and electroluminescence (EL) element).
In an image display device which performs image display with the use of an element which emits light or exhibits a color by voltage application or current supply, a memory is provided in a pixel in order to suppress power consumption due to repeated screen refresh operation during still image display. Once a still image display on the screen is completed, each display data can be retained in the memory in the pixel thereafter, which eliminates the need for refresh operation and stops the operation of a driver circuit for driving the pixel, so that power consumption can be lowered (Patent Document 1).